What is the best approach for welding a Comp Engineering sump to a stock tank. Notch the sump rails, or attack the tank. I'm figuring there must be a straight forward procedure. Thanks for any help.
Yep, the way Ive always done it is by using holes in a grid pattern and try to put them forward of the sump as possible. Leave a good inch or two at the back of tbe sump solid instead of holes, it makes a baffle effect during the launch so fuel doesnt try to "climb" out of tne back of the sump. When you use 4 or 5 small holes instead of 1 huge rectangle style hole acts like a baffle also.This is going to be my first tank, the directions that came with the sump want 2" holes drilled and the sump over that. I just need to be sure that I don't suck air for the fuel injection.
i have found that gas will eat right through rtv. make sure its welded correctly and pass on the rtv.<----- mig welded mine and then applied a layer of black rtv over the weld to ensure it does not leak. I used a 1" hole saw and punched 5 holes in it. I can run my car well below 1/4 tank around corners and under hard acceleration without any issues at all.
this is what I have been told to do as wella good way to get all of the fumes out is to obviously drain it, remove the sender. then take a hose (a shop vac one works), hook one end to the fill neck and the other to a vehicles exhaust pipe and run it for a while. the inert exhaust fumes will force out the gas vapor and then you are clear to weld. i did test mine first with a flame and it was fine.